kernel.git/tools/bpf/bpftool/main.c, branch linux-6.16.y

bpftool: Fix JSON writer resource leak in version command

2025-08-20T16:41:18Z

[ Upstream commit 85cd83fed8267cde0dd1cea719808aad95ae4de7 ] When using `bpftool --version -j/-p`, the JSON writer object created in do_version() was not properly destroyed after use. This caused a memory leak each time the version command was executed with JSON output. Fix: 004b45c0e51a (tools: bpftool: provide JSON output for all possible commands) Suggested-by: Quentin Monnet Signed-off-by: Yuan Chen Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20250617132442.9998-1-chenyuan_fl@163.com Signed-off-by: Sasha Levin

bpftool: Using the right format specifiers

2025-02-11T00:08:13Z

Fixed some formatting specifiers errors, such as using %d for int and %u for unsigned int, as well as other byte-length types. Signed-off-by: Jiayuan Chen Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20250207123706.727928-2-mrpre@163.com

bpftool: clean-up usage of libbpf_get_error()

2022-11-21T00:17:46Z

bpftool is now totally compliant with libbpf 1.0 mode and is not expected to be compiled with pre-1.0, let's clean-up the usage of libbpf_get_error(). The changes stay aligned with returned errors always negative. - In tools/bpf/bpftool/btf.c This fixes an uninitialized local variable `err` in function do_dump() because it may now be returned without having been set. - This also removes the checks on NULL pointers before calling btf__free() because that function already does the check. Signed-off-by: Sahid Orentino Ferdjaoui Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov

bpftool: remove support of --legacy option for bpftool

2022-11-21T00:17:46Z

Following: commit bd054102a8c7 ("libbpf: enforce strict libbpf 1.0 behaviors") commit 93b8952d223a ("libbpf: deprecate legacy BPF map definitions") The --legacy option is no longer relevant as libbpf no longer supports it. libbpf_set_strict_mode() is a no-op operation. Signed-off-by: Sahid Orentino Ferdjaoui Acked-by: Yonghong Song Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/r/20221120112515.38165-2-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov

bpftool: Check argc first before "file" in do_batch()

2022-11-16T05:36:24Z

If the parameters for batch are more than 2, check argc first can return immediately, no need to use is_prefix() to check "file" with a little overhead and then check argc, it is better to check "file" only when the parameters for batch are 2. Signed-off-by: Tiezhu Yang Acked-by: Stanislav Fomichev Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/r/1668517207-11822-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Alexei Starovoitov

bpftool: Add llvm feature to "bpftool version"

2022-10-25T17:11:57Z

Similarly to "libbfd", add a "llvm" feature to the output of command "bpftool version" to indicate that LLVM is used for disassembling JIT-ed programs. This feature is mutually exclusive (from Makefile definitions) with "libbfd". Signed-off-by: Quentin Monnet Tested-by: Niklas Söderlund Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20221025150329.97371-9-quentin@isovalent.com Signed-off-by: Alexei Starovoitov

bpftool: Add "bootstrap" feature to version output

2022-10-21T21:41:13Z

Along with the version number, "bpftool version" displays a list of features that were selected at compilation time for bpftool. It would be useful to indicate in that list whether a binary is a bootstrap version of bpftool. Given that an increasing number of components rely on bootstrap versions for generating skeletons, this could help understand what a binary is capable of if it has been copied outside of the usual "bootstrap" directory. To detect a bootstrap version, we simply rely on the absence of implementation for the do_prog() function. To do this, we must move the (unchanged) list of commands before do_version(), which in turn requires renaming this "cmds" array to avoid shadowing it with the "cmds" argument in cmd_select(). Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20221020100332.69563-1-quentin@isovalent.com

bpftool: Set binary name to "bpftool" in help and version output

2022-10-21T21:37:46Z

Commands "bpftool help" or "bpftool version" use argv[0] to display the name of the binary. While it is a convenient way to retrieve the string, it does not always produce the most readable output. For example, because of the way bpftool is currently packaged on Ubuntu (using a wrapper script), the command displays the absolute path for the binary: $ bpftool version | head -n 1 /usr/lib/linux-tools/5.15.0-50-generic/bpftool v5.15.60 More generally, there is no apparent reason for keeping the whole path and exact binary name in this output. If the user wants to understand what binary is being called, there are other ways to do so. This commit replaces argv[0] with "bpftool", to simply reflect what the tool is called. This is aligned on what "ip" or "tc" do, for example. As an additional benefit, this seems to help with integration with Meson for packaging [0]. [0] https://github.com/NixOS/nixpkgs/pull/195934 Suggested-by: Vladimír Čunát Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221020100300.69328-1-quentin@isovalent.com

bpftool: Clear errno after libcap's checks

2022-08-15T18:37:33Z

When bpftool is linked against libcap, the library runs a "constructor" function to compute the number of capabilities of the running kernel [0], at the beginning of the execution of the program. As part of this, it performs multiple calls to prctl(). Some of these may fail, and set errno to a non-zero value: # strace -e prctl ./bpftool version prctl(PR_CAPBSET_READ, CAP_MAC_OVERRIDE) = 1 prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = 1 prctl(PR_CAPBSET_READ, 0x2c /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, 0x2a /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, 0x29 /* CAP_??? */) = -1 EINVAL (Invalid argument) ** fprintf added at the top of main(): we have errno == 1 ./bpftool v7.0.0 using libbpf v1.0 features: libbfd, libbpf_strict, skeletons +++ exited with 0 +++ This has been addressed in libcap 2.63 [1], but until this version is available everywhere, we can fix it on bpftool side. Let's clean errno at the beginning of the main() function, to make sure that these checks do not interfere with the batch mode, where we error out if errno is set after a bpftool command. [0] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/tree/libcap/cap_alloc.c?h=libcap-2.65#n20 [1] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=f25a1b7e69f7b33e6afb58b3e38f3450b7d2d9a0 Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220815162205.45043-1-quentin@isovalent.com

bpftool: Do not check return value from libbpf_set_strict_mode()

2022-06-14T20:18:56Z

The function always returns 0, so we don't need to check whether the return value is 0 or not. This change was first introduced in commit a777e18f1bcd ("bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"), but later reverted to restore the unconditional rlimit bump in bpftool. Let's re-add it. Co-developed-by: Yafang Shao Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220610112648.29695-3-quentin@isovalent.com